2. The XF86Config File

The XF86Config file format is similar to the old format, with the following
changes:

2.1. Device section

The Device sections are similar to what they used to be, and
describe hardware-specific information for a single video card.
Device
Some new keywords are added:

Driver "drivername"

Specifies the name of the driver to be used for the card. This
is mandatory.

BusID "busslot"

Specifies uniquely the location of the card on the bus. The
purpose is to identify particular cards in a multi-headed
configuration. The format of the argument is intentionally
vague, and may be architecture dependent. For a PCI bus, it
is something like "bus:slot:func".

A Device section is considered ``active'' if there is a reference
to it in an active Screen section.

2.2. Screen section

The Screen sections are similar to what they used to be. They
no longer have a Driver keyword, but an Identifier keyword
is added. (The Driver keyword may be accepted in place of the
Identifier keyword for compatibility purposes.) The identifier
can be used to identify which screen is to be active when multiple
Screen sections are present. It is possible to specify the active
screen from the command line. A default is chosen in the absence
of one being specified. A Screen section is considered ``active''
if there is a reference to it either from the command line, or from
an active ServerLayout section.

2.3. InputDevice section

The InputDevice section is a new section that describes
configuration information for input devices. It replaces the old
Keyboard, Pointer and XInput
sections. Like the Device section, it has two mandatory keywords:
Identifier and Driver. For compatibility purposes the old
Keyboard and Pointer sections are
converted by the parser into InputDevice sections as follows:

Keyboard

Identifier "Implicit Core Keyboard"Driver "keyboard"

Pointer

Identifier "Implicit Core Pointer"Driver "mouse"

An InputDevice section is considered active if there is a
reference to it in an active ServerLayout section. An
InputDevice section may also be referenced implicitly if there
is no ServerLayout section, if the -screen command
line options is used, or if the ServerLayout section doesn't
reference any InputDevice sections. In this case, the first
sections with drivers "keyboard" and "mouse" are used as the core
keyboard and pointer respectively.

2.4. ServerLayout section

The ServerLayout section is a new section that is used to identify
which Screen sections are to be used in a multi-headed configuration,
and the relative layout of those screens. It also identifies which
InputDevice sections are to be used. Each ServerLayout section
has an identifier, a list of Screen section identifiers, and a list of
InputDevice section identifiers. ServerFlags options may also be
included in a ServerLayout section, making it possible to override
the global values in the ServerFlags section.

A ServerLayout section can be made active by being referenced on
the command line. In the absence of this, a default will be chosen
(the first one found). The screen names may optionally be followed
by a number specifying the preferred screen number, and optionally
by information specifying the physical positioning of the screen,
either in absolute terms or relative to another screen (or screens).
When no screen number is specified, they are numbered according to
the order in which they are listed. The old (now obsolete) method
of providing the positioning information is to give the names of
the four adjacent screens. The order of these is top, bottom, left,
right. Here is an example of a ServerLayout section for two
screens using the old method, with the second located to the right
of the first:

In the relative case, the position is specified by either using one of
the following keywords followed by the name of the reference screen:

RightOf
LeftOf
Above
Below
Relative

When the Relative keyword is used, the reference screen
name is followed by the coordinates of the new screen's origin
relative to reference screen. The following example shows how to use
some of the relative positioning options.

2.5. Options

Options are used more extensively. They may appear in most sections
now. Options related to drivers can be present in the Screen,
Device and Monitor sections and the Display subsections.
The order of precedence is Display, Screen, Monitor,
Device. Options have been extended to allow an optional value
to be specified in addition to the option name. For more details
about options, see the
Options section
for details.